#include <stdio.h>
#include <math.h>

int main(int argc, char *argv[])
{
	int n, i;
	double re;
	
	scanf("%d", &n);

	re = 0.0;
	for (i = 1; i <= n; i++) {
		re = re + pow(i, 2);
	}

	printf("%.0f\n", re);

	return 0;
}
